The present invention relates to apparatus for transporting flexible webs, especially photographic films, in containers. More particularly, the invention relates to improvements in apparatus for completing the transport of flexible webs in a direction toward and for convoluting the webs on rotary takeup devices whose web-collecting portions are confined in containers.
The processing of exposed photographic customer films in laboratories involves the removal of films from their containers and splicing of successive films end-to-end to form a long web which is thereupon transported through a developing and printing machine. Modern processing laboratories are equipped with devices which automatically remove exposed films from their containers and advance the removed films to a splicing station. The afore-mentioned web is convoluted onto a large reel which is thereupon transferred into the developing machine. Automatic removal of films from their containers (e.g., commercially available cassettes for roll films having 20 or 36 frames) necessitates winding of the entire film onto the takeup reel or spool in the container. Thus, if a customer sends in or delivers a container wherein one or more frames at the trailing end of the film remained unexposed, an attendant must rotate the takeup reel so as to insure that all frames of the film are convoluted on the core of the takeup reel before the container is introduced into the automatic film removing device. As a rule, containers for customer films are provided with hooks or analogous intercepting members which engage the trailing ends of films to prevent detachment of the trailing ends from the containers. The attendant notes the increasing resistance to rotation of the takeup reel when the hook engages the trailing end of the film and is thus apprised of the fact that the winding of film is completed. The hook and the material of the film offer a certain resistance to further rotation of the takeup reel in a direction to collect the film so that the engagement of trailing end with the hook is readily detectable. When the hook engages the trailing end (e.g., when the hook enters a perforation in the trailing end), a portion of the film in front of the trailing end extends across the customary exposure window which is provided in the casing of the container to admit light to successive film frames while the container is located in the chamber of a photographic apparatus, such as a still camera. That portion of the film which registers with the exposure window is then in an optimum position for expulsion of the trailing end of the film from the container and into the range of advancing rolls which move the trailing end (which is now the leader) of the film toward the splicing station. Reference may be had to commonly owned U.S. Pat. No. 3,921,878 granted Nov. 25, 1975 to Zangenfeind which discloses a suitable device for expulsion of photographic films from cassettes or analogous containers.
When the attendant detects that the film in a cassette is not fully convoluted onto the takeup reel, the latter is rotated by hand until the attendant notes that the film is taut, i.e., that the hook has entered the notch in the trailing end of the film. In accordance with presently prevailing practice, the attendant places the gear of the takeup reel into contact with a rack and moves the rack relative to the cassette to thereby wind the remaining unexposed frames of the film onto the takeup reel. It is also known to employ a simple crank which is inserted into the hole of the takeup reel and is rotated by hand. The just described procedures are acceptable for small-scale film development and further processing. However, the winding of a large number of films in a modern processing laboratory takes up too much time and is a tedious task requiring a substantial physical effort.
Another serious drawback of the just described conventional procedure is that the remaining frames of the film (i.e., those frames which must be convoluted onto the takeup reel) are exposed to light because successive increments of such frames must be transported past the exposure window on their way toward the core of the takeup reel. Therefore, such frames cannot be exposed during processing of the films for the purpose of exposing indicia (e.g., digits and/or characters) which are detected by certain components of the copying machine for the making of reproductions of some or all exposed and developed film frames. The indicia are also useful in assembling the exposed and developed films with corresponding prints prior to insertion of films and prints into envelopes or boxes preparatory to shipment to dealers or directly to customers.